ISIS surrenders leader Abu Bakr al-Baghdadi's hideout in Iraq

The Islamic State has surrendered the key town of Baaj in north-west Iraq, which was a known hideout of the terrorist group's leader Abu Bakr al-Baghdadi.

Baaj had been under Islamist militants' control throughout the 14 years of war and insurgency.

After the surrender, the remaining ISIS fighters fled the town on 3 June's night, allowing Shia militia forces to enter unopposed.

"The Iraqi flag has been hoisted above its buildings," a statement from the Popular Mobilisation Front, which is an umbrella organisation for pro-government paramilitaries that is dominated by Iran-backed Shia militias, announced the "total liberation" of the Baaj district.

The withdrawal leaves just a pocket of Mosul and the border town of Bukamal as the only urban centres in Iraq with a significant ISIS presence.

Bukamal is expected to be a new focus of both Iranian and U.S. efforts.

Meanwhile, U.S.-backed Kurdish troops are now within sight of Raqqa on three sides of the city and the battle to retake the city is likely to start sometime this month.